The invention generally relates to driver side air bags, modules and methods of folding an air bag.
The typical driver side air bag module comprises a housing, an inflator, an air bag and a cover. The housing is mounted at or near the hub of the steering wheel; the inflator and air bag are located within the housing and the cover protects the air bag. As the air bag inflates, the cover is broken apart thereby permitting the inflating air bag to expand. As can be appreciated, because the cover is a sacrificial part of the module it cannot be used to support permanent buttons, displays, switches and the like.
Another characteristic of the prior art construction is that on deployment, the expanding air bag is initially thrust directly toward the occupant, which may increase the level of forceful interference between the occupant and the expanding air bag. To restrict this forward motion, many prior art systems have resorted to the use of tethers, which attempt to control the trajectory of the expanding air bag.
It is an object of the present invention to provide an air bag module with a center control module that is fixed in relationship to the steering wheel and one in which the air bag and cover deploy about this fixed center control module. Consequently, an advantage of this construction is the fixed center module can now support control or communication mechanisms and devices such as a horn switch, radio dials, cruise control buttons and even more complicated and expensive visual displays for a navigation system, including GPS satellite receiver display. These additional mechanisms and devices will be unaffected by the deployment of the air bag and need not be repaired when a new air bag module is installed or can be reused in replacement air bag modules.
Another object of the invention is to provide a module in which the air bag is encouraged to initially fill radially due in part to the fixed center control module.
Accordingly the invention comprises: an air bag module, comprising an air bag, the air bag including: a circular face panel having a central, circular first opening; a circular rear panel of substantially the same diameter as that of the first panel and having a central, circular second opening, the diameter of the second opening being smaller than the diameter of the first opening. An inflatable, cylindrical tube member is secured to the face panel, about the first opening, the cylindrical member including a rectangular panel formed into a cylinder, closed at one end; the cylindrical member at an opposite second end is secured to the face panel about the first opening; at least one inflatable lobe secured about an opening in the cylindrical wall, the lobe on inflation of the air bag inflates inwardly toward the center of the face panel.
Many other objects and purposes of the invention will be clear from the following detailed description of the drawings.